Administration of botulinum toxin a and vascular endhotelial growth factor reduce norepinephrine levels and increase viability of modified mcfarlane flap in wistar rat

Abstract

Local hyperadrenergic states after a random flap elevation mediated by humoral vasoconstrictors can lead to flap necrosis. This study aimed to evaluate the effect of Botulinum Toxin A (BoNT-A) on reducing levels of Norepinephrine (NE) as the main humoral vasoactive substance, as well as its additive effect with Vascular Endothelial Growth Factor (VEGF) in increasing the viability of random flap. 28 Wistar Rats with Caudally Based Modified McFarlane Flap were divided into four groups. Group I received BoNT-A 3 days before flap elevation, group II received VEGF immediately after flap elevation, group III received a combination of BoNT-A and VEGF, group IV was a control group. Result in this study NE levels lowest was found in the BoNT-A+VEGF combination group (94.63 ± 5 .25 ng/ml, p<0.05 in group I, p<0.01 in groups II and IV). The highest value of FVR was shown in the BoNT-A+VEGF combination group (93.37 ± 2.19 %, p < 0.05 in group I, p < 0.01 in groups II and IV). Meanwhile, the increase in flap viability in the VEGF group was not statistically significant. So Conclusion administration of BoNT-A in combination with VEGF can increase the viability of random flaps by decreasing NE levels.